Winding element



1945. F. J. SIGMUND ETAL 2,383,019

- WINDING ELEMENT Filed June 4, I943 Patented Aug. 21, 1945 UNITED"STATES PATENT OFFICE WIN-DING ELEMENT Frank J. Sigmund and William S.Hlavin, Cleveland, Ohio, assignors, by' mesnei assignments, to'SigmundCorporation, a corporation of Ohio Application June 4, 1943, Serial No.489,614 a 4 Claims. ('01. 111-452) Our invention relates in general towinding elements forsa dynamo-electric machine and more particularly toliquid-tight. winding elements which may be submerged in liquid oroperated at high speeds and voltages and which will withstand a greatdeal of vibration without damage, and constitutes an improvement overour application. Serial No. 450,240, filedJuly 9, 1942, forLiquid-tight: stator. v

The term liquid-tight refers to the fact that the winding elements havebeen made tight by the use of rubber-like material or other similarmaterial which may be formed about the winding elements to render thewinding elements water-proof, dust-proof, insulation-proof andvibration-proof.

An object of our invention is the provision of forming or moldingrubber-like material about the windings of a dynamo-electric machine torender them liquid-tight.

Another object of our invention is the provision of embedding thewindings of a dynamoelectric machine in a mass of rubber-like materialwhich is relatively flexible and which will not. crack or be damagedbythe expansion and contractionof the magnetizable core incident tochanges in temperature.

Another object of our invention is the provision 'of anchoring thewindings to the magnetizable core prior to introducing a mass ofrubber-like material about the windings.

Another object of our invention is to cover or coat the surface of theslots of the magnetizable core with a rubber-like material to eliminatethe air-pockets on one side, and to cover the top and bottom heads ofthe windings, the free spaces between the windings on the other side,and to form complete vibration and water-proof elements.

Another object of our invention is to coat the entire coil sides andcoil heads with rubber-like material.

Other objects and a fuller understanding of our invention may be had byreferring to the accompanying description and claims, taken inconjunction with the drawing, in which:

Figure 1 is a cross-sectional view of a stator taken in conjunction withmolding dies employed to mold, or form the rubber-like material aboutthe windings of the stator;

Figure 2 is a cross-sectional View showing substantially one-half of arubber-like preformed sheet of material arranged to fit over the slotsand the ends of the magnetizable. core;

Figure 3 is a fragmentary and cross-sectional view taken through one ofthe slots after the sheet of material shown in Figure 2 has been appliedto the magnetizable core;

Figure 4 is a fragmentary and cross-sectional view of a, slot after thewindings have been molded in the rubber-like material; and

Figure 5 is a cross-sectional and fragmentary view of Figure 1 takenalong the line 5-5 thereof.

With reference to Figure 1 which shows a cross-sectional view of astator taken in conjunction with forming dies preparatory to forming.the rubber-like material about the windings of the stator to make aliquid-tight stator which m'aybe operatedunder water or other liquid,the

magnetizable core is identified by the reference character 20 whichcarries windings 2! comprising aplurality of coils positioned in thelongitudinal slots thereof. The portion of the coils which lie withinthe slots may be designated as coil 1 sides and the portion of the coilswhich extend beyond the ends of the magnetizable core 28 may bedesignated as coil heads. In the drawing, the coil'sides are indicatedby the reference character 22 and the coil heads by the referencecharacter 23. l The laminations of the magnetizable core 20' may be heldtogether in any suitable manner.

stantially the same as that shown and described incur pendingapplication Serial No. 488,170,

filed May 24, 1943 for Pre-formed coating for magnetizable core. The endflanges 26 of the preformed sheet of material 25 fits flat against theends of the magnetizable core. The preformed sheet of material is shownin Figure 2 and the portion which fits over the teeth is removed so thatthe air gap may be maintained to a mini -r'num. Instead of using apre-fo-rmed sheet of rubberlike material 25 as shown in Figure 2, therubber-like material may be applied to the magnetizable core by dippingthe core in a container having a, supply of rubber-like material such asshown and described in application Serial No. 482,710, filed April 12,1943 for Mag netiz-able core. In our invention, the rubberlike materialincludes a variety of substances in which the predominate part maycomprise polymers of vinyl compounds, such as vinyl chloride, vinylacetate, vinyl acetals and alcohols, and vinylid'ene chloride. It mayfurther include mixtures and copolymers of the vinyl compounds.

We find that the compounds identified above give very good results,however, we do not want to be specifically confined to these compoundsas our invention contemplates the use of any rubber-like material orsynthetic rubber to produce the insulation with the necessary propertiesrequired for the service conditions. It is within the scope of ourinvention to choose the best rubber-like compound with distinctivequalities which make that compound the most suitable for the insulationsuch as: (1) low water absorption, (2) high electrical resistance, (3)great resistance to chemicals, including acids, alkalies, corrosives andgases, (4) good tensile strength, (5) easy to app y to the magnetizablecore.

The softening point of the rubber-like material should be as high aspossible, thus permitting the temperature of the motor to rise to a highvalue. The rubber-like plastics or their compounds have a wide range oftemperature resistance and point of softening. Some begin to soften at140 F., others at 200 F. or more. Other grades can be employed with asoftening temperature higher than 200 F. and do not become brittle athub-zero temperatures and which have high dielectric and high tensilestrengths.

After the windings are inserted in the winding slots, they are anchoredto the magneti'zable core by means of an anchoring ring 30 and wrappingcord or tape 32. The anchoring ring 30 may be secured to the ends of thecore by means of screws 3| which pass through spacers to hold theanchoring ring 30 a short distance from the end of the core. Thewrapping cord or tape32 is looped around the anchoring ring and over thecoil heads 23. The anchoring ring and the wrapping cord or tape operateto hold the windings in the slots, and particularly prevents anyrelative longitudinal movement between the windings and the magnetizablecore. The wrapping cord or tape 32 comprises many loops which extendcompletely around the annular heads of the coils.

After the windings are secured within the slots the next operation is toassemble the core and the windings within a mold comprising generally alower part 33 and an upper part 34 held together by the bolts 35. Dieblocks 36 are mounted within the molds and cover the coil heads with aspace between the die blocks and the coil heads. A vacuum duct 31extends through the lower mold part 33 and the die block 36 to extractair from the winding assembly which is to be filled with the rubber-likematerial. Mounted within the central opening of the stator core is acylindrical valve sleeve 5| having a plurality of longitudinal slots 56which may be aligned with the slots of the core to permit therubber-like material to enter each of the winding slots and completelyfill all of the free space around the winding. The cylindrical valvesleeve 5| may be rotated by a handle 52 to either cause the slots 56 tobe aligned with the slots in the core or to permit the misalignment ofthe slots as requirements dictate. A packing nut 53 seals thecylindrical valve sleeve 5| with the lowermost portion of the lower moldpart 33. As illustrated, the mold is provided with a plurality of fluidjackets to heat the rubber-like material during the process of ejectingthe rubber-like material into the winding elements and to cool therubber-like material after the material has been injected into thewinding elements. The lower mold part 33 is provided with a fluid Jacket33 which has a duct 39 connected therewith for admitting heated liquidduring the molding process or to admit cold liquid during the settingprocess. The upper mold part 34 has around its body portion a fluidjacket 40 and a duct 4| connected thereto. The uppermost portion of theupper mold 34 has a fluid jacket 42 and a duct 43 extending therefrom.

An ejecting piston 48 and a cylinder 41 are connected to the upperportion of the upper mold part 34 by means of bolts or screws 49. Thecylinder 41 is provided with a fluid jacket 50 to heat the rubber-likematerial therein. Extending within the cylindrical valve sleeve 5| is afluid jacket 54 having a duct 55 connected thereto.

In operation, the rubber-like material is provided or supplied to thecylinder 41 below the piston 48 and the cylindrical valve sleeve 5| isturned or adjusted by the handle 52 so that the slots 56 within thecylindrical valve sleeve 5| are in alignment with the slots of the core,see Figure 5. As the piston 48 is depressed, the rubberlike material iscaused to flow downwardly through the orifice 44 and then into thecylindrical valve sleeve 5|. As the rubber-like material fiowsdownwardly, air may be exhausted through the vacuum duct 31. Therubber-like material fills all of the space about the coil sides withinthe slots and the coil head within the die blocks 36. Consequently, therubber-like material forms a fluid-tight envelope about the coil sidesand about the coil heads to render the winding elements water-proof,dust-proof, insulation-proof and vibration-proof. After the rubber-likematerial has completely filled all of the free space around the coilsides and the coil heads, the cylindrical valve sleeve 5| may be turnedto blank all communication through the slot 56, the blanking occurringwhen the slots 56 are in alignment with the ends of the teeth of thecore. The rubber-like material is heated to the proper temperature toenable it to fiow freely through all of the free spaces around thewindings to insure a complete water-tight job. The proper heating iscontrolled by determining the temperature of the fiuid which enters thefluid jackets through their respective connecting ducts. After thewindings are completely covered with the rubber-like material, theheated fluid may be removed from the fluid jackets, after which coolliquid may be caused to how into the fluid jackets through the connectedducts for cooling and set- .ting the rubber-like material. The cable 51which extends from the windings has its lower end anchored in therubber-like material which is formed around the coil heads so that afluidtight seal is provided where the cable enters the moldedrubber-like material which surrounds the coil heads. The vacuum duct 31also functions as an overflow for any excess rubber-like material whichaffords a signal that all of the free spaces about the winding arefilled.

The rubber-like material which is molded around the windings may be ofthe same composition as that for the sleeve winding 25 hereinbeforeidentified. More specifically, the rubberlike material which is moldedaround the windings may comprise vinol insulating compound, for example,VM 1890 which may be defined as natural colored, heat stabilizedcopolymer of vinol chloride and vinol acetate, medium high viscosityresin plus 35 to 50 percent plasticizer.

Instead of employing the rubber-like sleeve within the slots of the coreas hereinbefore illustrated, we may also employ the perforated sleevesas shown in our pending application Serial No. 450,240, filed July 9,1942 for Liquid-tight stator. These perforated sleeves would centralizethe windings in which event the rubber-like material would flow from thesupply chamber 4"! in and about the coil sides to completely fill thespace between the coil sides and the slots. In other words, theperforated sleeves would hold the coil sides a spaced radial distancefrom the slots to provide for the rubber-like material in the cylinderto fill all of the space instead of employing the material 25hereinbefore identified. One advantage Olf providing a sheet ofrubber-like material over the slots as shown in Figure 2, is that thesheet shown in Figure 2 may be previously tested for leaks to insurethat there is no likelihood of Water leaking into the stator after it isonce assembled.

Although we have described our invention with a certain degree ofparticularlity, it is understood that the present disclosure has beenmade only loy way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may beresorted to without departing from the spirit and scope of the inventionas hereinafter claimed.

We claim as our invention:

1. A liquid-tight elementior a dynamo-elem tric machine comprising amagnetizable core having a plurality of winding slots, a windingcomprising coils with coil sides in said slots and coil heads at theends of the core, fluid-tight insulating coating means in the slots tosubstantially envelop the coil sides, anchoring means at the ends of thecore and spaced therefrom, said anchoring means engaging and laterallysupporting the coils, binding means tying the coil heads to theanchoring means for longitudinally supporting the coils, and a mass offiuid-tight insulating material in the slots comprising in conjunctionwith the fluid-tight insulating coating means a liquid-proof containerabout each coil side, said mass of fluid-tight insulating materialterminating in an annular ring upon each end of the core and enclosingthe coil heads to make a liquid-tight winding.

2. A method for constructing a. liquid-tight element for adynamo-electric machine comprising a magnetizable core having aplurality of winding slots and a winding comprising coils with coilsides in said slots and coil heads at the ends of the core, comprisingthe steps of providing fluid-tight insulating coating means in the slotsto substantially envelop the coil sides, anchoring the coils to the coreto support the coils against both lateral and longitudinal movement, andin troducing a mass of fluid-tight insulating material in the slotswhich in conjunction with the fluid-tight insulating coating meansprovides a liquid-proof container about each coil side.

3. A method for constructing a. liquid-tight element for adynamo-electric machine comprising a, magnetizable core having aplurality of winding slots and a winding comprising coils with coilsides in said slots and coil heads at the ends of the core, comprisingthe steps of providing fluid-tight insulating coating means in the slotsto substantially envelop the coil sides, anchoring the coils to the coreto support the coils against both lateral and longitudinal movement,introducing a mass of fluid-tight insulating material in the slots whichin conjunction with the fluid-tight insulating coating means provides aliquid-proof container about each coil side, and applying a mass offluid-tight insulating material to the coil heads to render themliquid-tight.

4. A liquid-tight element for a dynamo-electric machine comprising amagnetizable core having a plurality of winding slots, a windingcomprising coils with coil sides in said slots and coil heads at theends of the core, anchoring means at the end' of the core and spacedtherefrom, said anchoring means engaging and laterally supporting thecoils, binding means tying the coil heads to the anchoring means forlongitudinally supporting the coils, and a mass of fluid-tightinsulating material in the slots for enveloping the coil sides toconstitute a liquidprooif container about each coil side, said mass offluid-tight insulating material terminating in an annular ring upon eachend of the core and enclosing the coil heads to make a liquid-tightwinding.

FRANK J. SIGMUND.

WILLIAM S. HLAVIN.

